Somewhat concurrently with a growing concern for handicapped persons, improved structures have been proposed for accommodating people either in wheelchairs or otherwise having limited mobility. In that regard, moving an occupied wheelchair in and out of a vehicle has presented one of the more challenging problems of attaining mobility for handicapped persons.
Generally, considerations relative to an effective wheelchair lift have included safety, ease of use, economy, space requirements and durability. Although a variety of mechanisms and structures have been proposed, a need has persisted for an improved lift to transport persons in wheelchairs in and out of vehicles.
One form of previously proposed wheelchair lift included a platform carriage, horizontally moveable between a stowed position within a vehicle and a deployed position outboard of the vehicle. A platform, in the carriage, was mounted to swing in an arcuate path for lifting and lowering a wheelchair between ground level and the floor level of the vehicle. As an example of such lifts, see U.S. Pat. No. 4,134,504, to Salas, et al. Generally, the system of the present invention is directed to wheelchair lifts of such a class or category, i.e., a horizontally stowable carriage with pivotal platform.
In the past, lifts as described above have been useful and effective; however, as indicated, the need for improvement has persisted. For example, it is important to provide a horizontally moveable mechanism that is capable of smooth motion without binding or catching between the stowage and deployed positions. As a further consideration, effectively aligning the platform for stowage is important as is providing a control system that is somewhat foolproof. Additionally, safety, economy and durability remain significant considerations with regard to an improved lift.
In general, a lift in accordance herewith includes a travelling assembly comprising a carriage, an elevating frame and a platform, horizontally moveable relative to a vehicle between inner (stowed) and outer (deployed) positions. A mounting enclosure, attached to a vehicle receives the travelling assembly. As part of the travelling assembly, a parallelogram lifting arrangement, including pivotal connections is fixed between the platform and the carriage. Drive or motive means raise and lower the platform as it travels an arcuate path. Specifically, as disclosed, the motive means is connected to the parallelogram elements connected to the upper pivot.
As a further aspect of the disclosed embodiment, the spaced-apart guide rails may be curved or incorporate an angle so that the travelling unit changes its orientation as it moves between inner and outer positions. Also, the parallelogram mechanism may be modified to change the inclination of the platform as it is raised or lowered. That is, when the platform is raised or lowered by a modified or irregular parallelogram, the inclination of the platform changes with reference to the horizontal. This is believed to be a unique safety feature.
In another aspect, the invention provides a vehicle lift including a travelling assembly moveable on lateral rails each comprising an elongate guide rail spaced from a support and engageable by cam followers. The system accordingly provides a lift for passengers who may be in wheelchairs, to be used with a vehicle, comprising a travelling assembly moveable in relation to a vehicle between inner and outer positions and including: a platform, an elevating frame and a carriage. The travelling assembly is received for stowage in a mounting enclosure.
The invention further provides a lift that may be effectively mounted beneath the floor of a vehicle, substantially without offending protrusions when stowed, and including a platform moveable between retracted (stowed) and extended (deployed) positions, the platform in the extended position being further moveable in an arcuate path between lower and raised positions to carry a load, i.e., a person in a wheelchair between ground level and the vehicle floor level.